Schizophrenia in people with intellectual disability: the role of pregnancy and birth complications

Preeclampsia and Neurodevelopmental Outcomes: Potential Pathogenic Roles for Inflammation and Oxidative Stress?

Preeclampsia (PE) is a common and serious hypertensive disorder of pregnancy that occurs in approximately 3-5% of first-time pregnancies and is a well-known leading cause of maternal and neonatal mortality and morbidity. In recent years, there has been accumulating evidence that in utero exposure to PE acts as an environmental risk factor for various neurodevelopmental disorders, particularly autism spectrum disorder and ADHD. At present, the mechanism(s) mediating this relationship are uncertain. In this review, we outline the most recent evidence implicating a causal role for PE exposure in the aetiology of various neurodevelopmental disorders and provide a novel interpretation of neuroanatomical alterations in PE-exposed offspring and how these relate to their sub-optimal neurodevelopmental trajectory. We then postulate that inflammation and oxidative stress, two prominent features of the pathophysiology of PE, are likely to play a major role in mediating this association. The increased inflammation in the maternal circulation, placenta and fetal circulation in PE expose the offspring to both prenatal maternal immune activation-a risk factor for neurodevelopmental disorders, which has been well-characterised in animal models-and directly higher concentrations of pro-inflammatory cytokines, which adversely affect neuronal development. Similarly, the exaggerated oxidative stress in the mother, placenta and foetus induces the placenta to secrete factors deleterious to neurons, and exposes the fetal brain to directly elevated oxidative stress and thus adversely affects neurodevelopmental processes. Finally, we describe the interplay between inflammation and oxidative stress in PE, and how both systems interact to potentially alter neurodevelopmental trajectory in exposed offspring.

Comorbidities in children with intellectual disabilities

BACKGROUND

Intellectual disability (ID) is registered in 2%-3% of newborns. In most cases, the causes are not identifiable.

OBJECTIVE

We explored the correlation between the intellectual disability and gestational age, birth weight, Apgar score, familial diseases, congenital anomalies, and acquired medical disorders, with the aim to estimate the prevalence and severity of comorbidities in the affected children.

METHODS

Our study included 22 children with ID, and 24 with proper psychomotor development, aged 5-10 who were not considered to have ID.

RESULTS

The presence of familial disorders and CNS congenital anomalies increased the risk of ID 4.147 and 2.59 times, respectively. The risk for other congenital and noncongenital diseases was higher (7.38 and 1.4 times, respectively) in children with intellectual disability.

CONCLUSIONS

Children with intellectual disabilities have higher incidence of congenital diseases, family disorders and a higher frequency of acquired disorders during childhood. Apgar score is a sensitive predictor of morbidity regarding congenital as well as noncongenital medical conditions.

Early intervention in psychosis: clinical aspects of treatment

Engaging patients in first-episode psychosis services is critical in maximising the effect of early intervention and establishing a framework for longer-term treatment. Biopsychosocial assessments determine a working diagnosis and inform evidence-based treatment. Atypical antipsychotics should be used at doses that maximise therapeutic benefit and adherence while minimising side-effects. Patients are helped to construct a narrative of their illness, including a shared understanding of the contribution of biological and environmental risks, and early warning signs. Common comorbid conditions, including depression, suicidal ideation, substance misuse and anxiety, should be addressed. Management of comorbid borderline and antisocial personality disorders is difficult; their nexus with psychosis is discussed. Cognitive–behavioural therapy is a mainstay of treatment, with specific interventions developed for problems typical in first-episode presentations. Core psychosocial interventions include psychoeducation, vocational and educational support, family interventions and multimodal group programmes.

Psychiatric disorders amongst adults with learning disabilities - prevalence and relationship to ability level

Objectives: To determine the prevalence of psychiatric disorders in adults with learning disabilities, and the relationship with severity of learning disabilities.

Method: The study is population-based. Detailed psychiatric assessments on 207 adults with learning disabilities living in Leicestershire, UK. were conducted by a learning disabilities psychiatrist, using the Present Psychiatric State - Learning Disabilities; and Disability Assessment Schedule. Diagnostic criteria are clearly defined. Developmental assessments were undertaken using the Vineland Scale (survey form).

Results: Psychiatric disorders were found in 49.2%, and rates for most individual disorders were higher than those found in the general population. Comparison with the two previous population-based studies shows the ascertained rates were broadly similar to those reported by Corbett but higher than those reported by Lund. Adults with more severe learning disabilities had higher rates of additional psychiatric disorders.

Conclusions: The results may be explained by a combination of the genetic, physical, psychological and social factors associated with learning disabilities also being aetiological to psychiatric disorders. The high prevalence rates of psychiatric disorders demonstrate the importance of health service provision for adults with learning disabilities.

Hypertensive disorders in pregnancy and risk of severe mental disorders in the offspring in adulthood: the Helsinki Birth Cohort Study

BACKGROUND

Hypertensive disorders may affect the fetal developmental milieu and thus hint at mechanisms by which prenatal adversity associates with mental disorders in later life. We examined if hypertension without proteinuria and preeclampsia in pregnancy predict serious mental disorders in the offspring, and if sex, childhood socioeconomic status, length of gestation and parity modify these associations.

METHODS

We included 5970 women and men born after a normotensive, hypertensive or preeclamptic pregnancy defined by using mother's blood pressure and urinary protein measurements at maternity clinics and birth hospitals. Mental disorders requiring hospitalization or contributing to death were identified from the Finnish Hospital Discharge and Causes of Death Registers between years 1969 and 2004.

RESULTS

In comparison to the offspring born after normotensive pregnancies, offspring born after pregnancies complicated by hypertension without proteinuria were at 1.19-fold (CI: 1.01-1.41, P-value = 0.04) higher risk of any mental disorder and 1.44- (CI: 1.11-1.88, P-value < 0.01) and 1.39-fold (CI: 0.99-1.93, P-value = 0.05) higher risk of mood and anxiety disorder, respectively. In contrast, preeclampsia was associated, with a lower risk of any mental disorder in the male offspring (P-value = 0.02; P-value = 0.04 for interaction 'sex × normotension/preeclampsia').

CONCLUSIONS

Hypertension without proteinuria in pregnancy was associated with a higher risk of serious mental disorders in the offspring in adulthood. Preeclampsia seems to, in turn, associate with lower risk of severe mental disorders in male offspring.

A retrospective population-based data analyses of inpatient care use and medical expenditure in people with intellectual disability co-occurring schizophrenia

The paper aims to analyze the hospital inpatient care use and medical fee of people with ID co-occurring with schizophrenia in Taiwan. A nationwide data were collected concerning hospital admission and medical expenditure of people with ID (n = 2565) among national health insurance beneficiaries in Taiwan. Multiple regression analyses were undertaken to determine the role of the explanatory variables to hospital psychiatric inpatient care and medical expenditure. We found that there were 2565 individuals with ID used hospital psychiatric inpatient care among people with ID in 2005, and 686 cases (26.7%) co-occurring with schizophrenia according to hospital discharge claims. Those ID patients co-occurring with schizophrenia consumed more annual inpatient fee than those without schizophrenia (251,346 vs. 126,666 NTD) (p < 0.001). We found factors of female cases, longer hospital stay in chronic ward and general ward users among ID patients co-occurring with schizophrenia used more hospital inpatient care (R(2) = 0.417). Annual hospital inpatient days were significantly affected by factors of severe illness card holder, annual inpatient care fee, longer hospital stay in acute or chronic ward (R(2) = 0.746). Those factors of female cases, high inpatient care users, longer hospital stay in acute ward and general ward were consuming more medical care fee than their counterparts (R(2) = 0.620). The study highlights the future study should examine the efficacy of hospital inpatient care for people with ID and schizophrenia.

Beyond the first episode: candidate factors for a risk prediction model of schizophrenia

Many early psychosis services are financially compromised and cannot offer a full tenure of care to all patients. To maintain viability of services it is important that those with schizophrenia are identified early to maximize long-term outcomes, as are those with better prognoses who can be discharged early. The duration of untreated psychosis remains the mainstay in determining those who will benefit from extended care, yet its ability to inform on prognosis is modest in both the short and medium term. There are a number of known or putative genetic and environmental risk factors that have the potential to improve prognostication, though a multivariate risk prediction model combining them with clinical characteristics has yet to be developed. Candidate risk factors for such a model are presented, with an emphasis on environmental risk factors. More work is needed to corroborate many putative factors and to determine which of the established factors are salient and which are merely proxy measures. Future research should help clarify how gene-environment and environment-environment interactions occur and whether risk factors are dose-dependent, or if they act additively or synergistically, or are redundant in the presence (or absence) of other factors.

Psychosis and adults with intellectual disabilities. Prevalence, incidence, and related factors

OBJECTIVE

To determine the point prevalence, incidence, and remission over a 2-year period of psychosis in adults with intellectual disabilities, and to investigate demographic and clinical factors hypothesised to be associated with psychosis.

METHOD

A population-based cohort of adults with intellectual disabilities (n = 1,023) was longitudinally studied. Comprehensive face-to-face mental health assessments to detect psychosis, plus review of family physician, psychiatric, and psychology case notes were undertaken at two time points, 2 years apart.

RESULTS

Point prevalence is 2.6% (95% CI = 1.8-3.8%) to 4.4% (95% CI = 3.2-5.8%), dependant upon the diagnostic criteria employed. Two-year incidence is 1.4% (95% CI = 0.6-2.6), and for first episode is 0.5% (95% CI = 0.1-1.3). Compared with the general population, the standardised incidence ratio for first episode psychosis is 10.0 (95% CI = 2.1-29.3). Full remission after 2 years is 14.3%. Visual impairment, previous long-stay hospital residence, smoking, and not having epilepsy were independently associated with psychosis, whereas other factors relevant to the general population were not.

CONCLUSIONS

The study of psychosis in persons with intellectual disabilities benefits the population with intellectual disabilities, and advances the understanding of psychosis for the general population. Mental health professionals need adequate knowledge in order to address the high rates of psychosis in this population.

Gene regulation by hypoxia and the neurodevelopmental origin of schizophrenia

Neurodevelopmental changes may underlie the brain dysfunction seen in schizophrenia. While advances have been made in our understanding of the genetics of schizophrenia, little is known about how non-genetic factors interact with genes for schizophrenia. The present analysis of genes potentially associated with schizophrenia is based on the observation that hypoxia prevails in the embryonic and fetal brain, and that interactions between neuronal genes, molecular regulators of hypoxia, such as hypoxia-inducible factor 1 (HIF-1), and intrinsic hypoxia occur in the developing brain and may create the conditions for complex changes in neurodevelopment. Consequently, we searched the literature for currently hypothesized candidate genes for susceptibility to schizophrenia that may be subject to ischemia-hypoxia regulation and/or associated with vascular expression. Genes were considered when at least two independent reports of a significant association with schizophrenia had appeared in the literature. The analysis showed that more than 50% of these genes, particularly AKT1, BDNF, CAPON, CCKAR, CHRNA7, CNR1, COMT, DNTBP1, GAD1, GRM3, IL10, MLC1, NOTCH4, NRG1, NR4A2/NURR1, PRODH, RELN, RGS4, RTN4/NOGO and TNF, are subject to regulation by hypoxia and/or are expressed in the vasculature. Future studies of genes proposed as candidates for susceptibility to schizophrenia should include their possible regulation by physiological or pathological hypoxia during development as well as their potential role in cerebral vascular function.

Schizophrenia-spectrum psychoses in people with and without intellectual disability

BACKGROUND

Although there is an increased risk of schizophrenia-spectrum psychoses (SSP) in people with intellectual disability (ID), there is a paucity of research evidence into clinical presentation of the disorder in comparison with research into SSP in people without ID.

AIMS

The aims of the study were to compare clinical, functional, and social factors in patients with mild ID (ICD-10: F70) and SSP (ICD-10: F20-9) attending a specialist mental health service for people with ID, with a control group of patients without ID but with SSP attending a generic adult mental health (GAMH) outpatient clinic.

METHOD

A total of 106 patients with SSP (53 with ID and 53 from GAMH) were assessed on psychopathological symptoms, functioning scales and quality of life. They were compared using chi-squared and regression analysis where appropriate.

RESULTS

People with ID and SSP appear to be more debilitated by the co-occurring disorder than those with the same disorder but without ID. Increases in observable psychopathology and "negative" schizophrenic symptoms, and decreased functional abilities were observed in the group with ID when compared to the GAMH group. The clinical implications of these findings are discussed.

Postmaturity in a genetic subtype of schizophrenia

OBJECTIVE

To determine whether postmaturity (gestation > 41 weeks), small for gestational age (SGA), and other pregnancy and birth complications that may elevate risk for neurodevelopmental disorders, are associated with elevated risk for schizophrenia in 22q11 Deletion Syndrome (22qDS), a genetic subtype of schizophrenia.

METHOD

Antepartum and intrapartum features were examined in 20 adults with 22qDS-schizophrenia and three comparison groups: newborn encephalopathy (n = 164) and healthy newborn controls (n = 400) from Badawi et al.'s (Br Med J 1998, 317: 1549) study, and 16 non-psychotic 22qDS adults (22qDS-NP).

RESULTS

Postmaturity (OR 13.0, 95% CI 3.95, 42.77; P < 0.001) and SGA (OR 3.59, 95% CI 1.23, 10.5; P = 0.03) were more prevalent in 22qDS-SZ than controls. Postmaturity was non-significantly more prevalent in 22qDS-SZ than in newborn encephalopathy (P = 0.06) or 22qDS-NP (P = 0.2). SGA showed similar rates in the two 22qDS groups and newborn encephalopathy, but was more prevalent in 22qDS-NP than controls (P = 0.05).

CONCLUSION

The results suggest that postmaturity may be associated with expression of schizophrenia in a 22qDS subtype of schizophrenia. SGA may be a non-specific marker of neurodevelopmental disturbance.

Correlations between clinical and historical variables, and cerebral structural variables in people with mild intellectual disability and schizophrenia

The increased prevalence of schizophrenia in the population with mildly intellectual disability (ID) remains unexplained. The present study explores several possibilities by examining historical/clinical findings in relation to structural neuroimaging findings in three groups: (1) comorbid mild ID and schizophrenia; (2) schizophrenia alone; and (3) mild ID alone. Information about clinical and historical variables was obtained from 101 subjects (39 with comorbidity, 34 with schizophrenia and 28 with mild ID), out of whom 68 (23, 25 and 20, respectively) had had a cerebral magnetic resonance imaging (MRI) scan. Although a number of significant correlations exist between clinical variables and structural MRI abnormalities in all three groups, no clearly predictive inter- or between-group differences emerged. More striking was the finding that showed small amygdalo-hippocampal size to be associated with a history of central nervous system injury, especially meningitis. These findings provide support for the view that cognitive impairment and comorbid psychosis can result from a common cause, such as meningitis or obstetric complications, possibly interacting with other factors, such as family history.

The miseries of passive smoking

Passive smoking is defined as an involuntary exposure to a combined but diluted cigarette sidestream smoke (SS, gas and particle phases that are evolved from the smoldering end of a cigarette while the smoker is not puffing) and the exhaled smoke from smokers. SS contains numerous cytotoxic substances such as polycyclic aromatic hydrocarbons (PAHs), aromatic amines, nitrosamines, heavy metals, poisonous gases, pesticide residues, and radioactive elements in quantities much higher than those found from the cigarette mainstream smoke (MS) which is puffed by smokers. Passive smoking is found to be the cause of death from cancers and cardiac disease. Furthermore, it damagingly involves reproductive organs, the nervous system, genetic materials, and is particularly hazardous to mother and child during pregnancy and to those with a history of asthma, chronic infections, induced or earned immune deficiency, or predisposed susceptibility.

Lifetime prevalence of schizophrenia among individuals prenatally exposed to atomic bomb radiation in Nagasaki City

OBJECTIVE

The aim of this study was to examine the relationship between prenatal exposure to atomic bomb (A-bomb) radiation and the development of schizophrenia in adulthood.

METHOD

We investigated the lifetime prevalence of schizophrenia among people prenatally exposed to the 1945 Nagasaki A-bomb, using the schizophrenia register and the A-bomb survivors' database.

RESULTS

Among 1867 prenatally exposed individuals, 18 subjects (0.96%) had developed schizophrenia later in life. The prevalence was significantly higher in people exposed in the second trimester of pregnancy than in those exposed in the third trimester. The closer they had been to the hypocentre, the higher was the prevalence, but no statistically significant linear relationship was seen.

CONCLUSION

This investigation could not clarify the nature of exposure to A-bomb radiation as a risk factor for schizophrenia in the prenatal period.